Significant advances of recent years in computer graphics and image processing technologies, used in the field of computer games or digital broadcasting, have enabled more exquisite displaying of three-dimensional (3D) images or other objects on the screen. Polygons representing objects in 3D space or two-dimensional (2D) images input by users are sent to a display apparatus or the like as pixel-based digital image information.
When representing, on a pixel-by-pixel basis, images that originally have been analog information, or line segments connecting vertices with known coordinates, the method therefor is selected in accordance with desired processing speed or rendering accuracy, or ease of the hardware implementation.
Pixels are arranged discretely. Therefore, when converting a graphic to be rendered into pixel-based data, a case may occur in which the graphic appears with jagged edges, called jaggies, due to the contour of the constituent pixels of the graphic appearing on the image, or with thin lines fragmented. These phenomena are generally called aliasing, and anti-aliasing methods, such as rendering at a higher resolution, have been devised to reduce such phenomena (see Non-Patent Document 1, for example).
[Non-Patent Document 1] Chengyu Sun et. al., “Hardware Acceleration for Spatial Selections and Joins,” UCSB Technical Report (2002-17).